Measuring apparatus



July 5, 1932. A. EA YOUNG 1,865,996

MEASURING APPARATUS Original Filed Aug. 1. 1929 4 Sheets-Sheet 1 EJEEUZJuly 5, 1932. A. E. YOUNG MEASURING APPARATUS Original Filed Aug. l,1929 4 Sheets-Sheet 2 INVENTOR Sheets-Shed. 3

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July 5, 1932. -A E, YOUNG A MEASURING APPARATUS original Filed Aug. 1,1929 4 sheelts-sheet 4 INVENTOR Patented July 5, 1932 sATES PATENTOFFICE MEASURING- APPARATUS Continuation of application Serial No.382,692, iled 1929. Serial My invention relates, primarily, to themeasurement of gas flo-wing in a main, and consists, first of all, inapparatus which shall afford direct reading in units of volume of thequantity of gas passed, with correction for variations in pressure. Theapparatus of my invention, in its further elaboration, has the capacityor characteristic of affording direct reading of quantity, withcorrection for variations in a plurality of circumstances whichseverally affect volume. In another aspect of my invention, it consistsin apparatus of wide and general applicability, for making summation of,or determining the resultant of, a plurality of variable quantities. Ishall first describe the invention in its application to the measurementof gas as it flows in a main. This application is a continuation of anapplication filed by me August l, 1929, Serial No. 382,692.

In the accompanying drawings Fig. I is a view in vertical section of aninstrument embodying my invention and adapted to afford by directreading in units of volume the quantity of gas flowing through anorifice or other restricted passageway within a gas main; Fig. II is aview to larger scale, showing in end elevation one of the rotary memberswhich form part of the organization; Fig. III is a fragmentary view insection also to larger scale than Fig. I, and showing in side elevationthe same rotary member, with greater elaboration of detail than appearsin Fig. 1; Fig. IV is a view corresponding to Fig. I and illustratingcertain elaborations and certain adaptations of the invention; Fig. V isa view corresponding to Fig I and illustrating other adaptations; Fig VIis a diagrammatic view showing, fragmentarily, operating the levers suchas those shown in Fig. I; these operating levers in Fig. VI being shownto be associated with and subject to operation in response to certainelectrical devices. Thus the invention is made applicable in furtherfields of industry.

In the measurement of gas two systems have been in vogue. One involvesdirect volumetric measurement--the alternate filling and emptying of achamber of known capacw ity with gas. The other is an indirect systemAugust 1, 1929. This application filed. 'October 12, No. 400,99?.

-the gas is caused to flow with fall in pressure through an orifice orother constricted passageway of known size, and such conditions beingestablished, the rate of flow is measured-so much gas passes per unit oftime. In the system of direct measurement, supplementary apparatus hasto be provided for noting the pressure to which the gas while beingmeasured is subject, and correction of the meter reading has to be madeby calculation from the data concerning pressure, in order to obtain an,approximately dependable figure. In practice according to the secondsystem also, a record of pressure must be kept, and from the datarecorded the quantity of gas passing is, with a fair degree of accuracy,computed.

Referring rst to Fig. I of the drawings, a casing 1 is provided, withinwhich a long lever 2 is pivoted. This lever 2, pivoted at 25, isorganized, as diagrammatically indicated in Fig. I, with an orificedplate 24 in a gas main, in such manner that it swings in response tovariation in the differential pressure-that is to say, in thepressuredrop from the upstream side to the downstream side of theorifice. Such elementary organization is well known, and requiresnofurther illustration. It has, as I have already intimated, long beencommon practice to observe the range of swing of such an arm and,observing also by other particular means variations in the staticpressurethat'is to say in the actual pressure to which the gas stream issubject-@to calculate the quantity of gas which during the time ofobservation actually passes through the orifice. Such procedure iscomplicated and time consuming and, though theoretically capable ofaording accuracy, is subject to the practical difliculty of ascertainingwith accuracy what the variations in actual pressure may be. And, inpassing, I remark that 1n my apparatus there is the possibility of suchminute shaping of the parts that each instrument may by reference to anormal be standardized, to afford under all conditions within the rangeof contemplated service substantially perfect accuracy.

The lever 2 at its distal end is slotted longitudinally and carriesfreely reciprocable in the slot la block 3. Block 3 is engaged also by aguideway 4 which extends transversely tothe length of arm 2. As the arm2 swings in response to variation in the differential pressure of thegas flowing through the orifice, block 3 will move up and down inguideway 4, and, the arm 2 being relatively long and being so organizedthat within the limits of ordinary operation its angular range of swingis small, the movement of block 3 along the guideway'will .always beclosely proportional to the variation in differential pressure. If itwere a matter of direct readin of theposition of the block along theguideway, the inaccuracy due to the fact that the right-line movement ofthe block is not minutely proportional to the angular swing of thelever, would be inconsiderable; but, by virtue of the fact that theblock cooperates with other mechanical parts, proportions may be so farmodified and adapted as to eliminate even such a sli ht andinconsiderable inaccuracy.

n proximity to, and in parallelism with the pathway' of block 3 in itsguideway, extends a constantly and uniformly advancing surface. In theparticular instrument here illustrated, this surface is the surface of acylinder 5, mounted for rotation on an axis parallel with the pathway ofblock 3 and rotated at constant speed by suitable means, in this casethe motor 6'. The block 3 is vequipped with a brush 7 (cf. Figs. II andIII) 9 is so particularly shaped and disposed that at successive pointslongitudinally of the cylinder the distance between the strips, measuredcircumferentially, is proportional to the square root of the distance atwhich the block 3, ranging longitudinally'of the cylinder, is remotefrom a zero point. With reference to the instrument of Fig. I of thedrawings, the strips 8 and 9, being prolonged, would meet at or near theupper-end of the cylinder. When the differential pressure in the gasmain is zero, there is of course no flow; and, while that conditionobtains, the'lever 2 (Fig. I) is in a position upwardly inclined fromleft to right, and the brush 7 which block 3 bears is just free ofcontact with the strips at their meeting point. As the differentialpressure increases from zero through the range of service value, thelever 2 swings clockwise, and the block 3 moves from the zero pointdownward along the guideway 4;

and at successive points in the range of'block.v

movement, the distance between the strips, measured circumferentially,is proportional to the square root of the distance at which block 3stands remote from the zero point. It will be understood that in thisrespect the drawings are diagrammatic; no attempt has been made so toplot the position of strip 9 as to render the drawing a literalpresentation of the equation stated.

A shaft 10 is mounted for rotation coaxially with cylinder 5. Shaft 10carries integrally a clutch member, in the form of a disk 11. Cylinder 5carries one or more clutch members, in the form of swinging arms 12,which extend longitudinally beyond the head of the cylinder and oppositethe face of disk 11. The arms may be swung to and from engagement withthe disk. The face of the disk and the outer ends of the arms aresuitably adapted to serve the clutch purpose indicated. To such end, theface of the disk may be serrated, and the arms may terminate in teethadapted-to enter and to be withdrawn from engagement with theserrations. Such minute shaping of the parts is indicated in thedrawings. Conveniently there are two arms 12, arranged in diametricallyopposite positions on cylinder 5. Normally the arms l2 are held bysprings 13 in the retracted posil -tion indicated in Fig. I, and fromthis position they are swung inwardly, 'against the tension of thesprings, by means of electromagnets 14. These magnets are borne bycylinder 5 and are so situated that, when energized, they attract anddraw the arms inward; and, to effect this end, the arms are formed ofmagnetic material, or carry blocks of magnetic material suitablysituated.

Cooperating with the arms 12 are spring latches l5, borne also bycylinder 5. In Fig. II, the latches 15 are shown in inactive positionbearing under the tension of spring 16 upon opposite surfaces of thearms 12. When, by the energizing of electro-magnets 14, the arms 12 areswung inward to clutch-closing position, the latches, which under thetension of springs 16 had been bearing laterally uponthe sides of thearms, spring to place behind the arms, and hold them secure in theirclutchclosing position.

A second pair of electro-magnets 17 is provided, borne also by cylinder5, and so arranged that, when energized (in alternation 5, s longas theclutch is closed. When the clutch is open, shaft is at rest.

The parts of the electrical apparatus are diagrammatically shown: 18(Fig. I) is a 5 suitable source of electrical energy; 19 is a relay; 2Oand 21 are collector rings borne by and insulated upon the rotatingshaft of cylinder 5. The ring 2O is complete and continuous; the ring 21is composed of two arc- 0 shaped parts, insulatedone from the other. Oneof the arc-shaped partsvof ring 21 is electrically connected with thecoils of magnets 14, the other with the coils of magnets 17.

When in the course of cylinderV rotation l 5 the brush 7 with whichblock 3 is equipped makes contact with strip 8, a circuit is closedwhich may be traced in Fig. I from the contact strip 8, through Aring 2Oto source 18, and from source 18 through the coil ot the solenoid whichoperates a relay switch 19,

and thence to the brush 7, borne by block 3,

which brush at the moment, is in contact with strip 8. Immediately uponthe completion of this circuit relay 19 is operated, and then 5 thecurrent in full strength flows through magnets 14, energizes them, andcloses the clutch. This magnet-energizing circuit may be traced in Fig.I from the source 18 through the relay 19 to the ring 21; from the 0ring 21 through the coils of the two electro magnets 14, thence to thering and Jfrom ring 20 back again to the source 18. It will beunderstood that by suitable proportioning of resistances the currentwhich flows in the 5 relay-actuating circuit may be relatively light andthat the magnet-operating circuit may be relatively heavy, as needrequires that it be. And it will be particularly remarked that Whereasthe tirst circuit, the relatively light relay-actuating circuit, iscompleted through the contact of brush 7 upon strip 8, the relativelyheavy magnetactuating circuit does not include the parts 7 and 8.Accordingly, a tendency to spark- 5 ing is avoided; a. sparking whichmight occur on the making and breaking of contact of brush 7 withstrip8, Were the magnetactuating circuit completed through that contact.When magnets 14 have' been ener- 9 gized they draw the arms 12 towardthemselves and in so doing close the clutch. The latches 15automatically close behind the clutch arms 12. When, in the continuingrotation of the cylinder 5, the brush 7 passes 5 from contact with thestrip 8, the solenoid which controls the operation of the relay 19 willbe de-energized. It will be understood that on the de-energizing of thissolenoid the relay 19 will open, and when the relay 0 19 opens themagnet-actuating circuit also will be broken. Although themagnet-actuating circuit is by the advance ofthe brush 7 from contactwith the strip 8 broken, the clutch remains closed, secured by latches15. J The shaft 10, which up to the moment 'of magnet-actuation had beenat rest, Jfrom that moment forward rotates in unison with the cylinder.In the further progress of operation the brush with `which block 3 isequipped makes Contact with strip 9. The same circuit through thesolenoid of relay 19 is completed again and the relay is closed. 'Ihesecond circuit, the circuit closed by the relay, is a circuit which nowis closed, not through electro-magnets 14, but, because of the turningof ring 21, through electro-magnets 17. The energizing of magnets 17effects the opening of the latches 15, and in consequence the clutcharms 12, released from restraint, swing outward under s ring tension,the clutch is opened, and the s aft 10 stops.

In Fig. I of the drawings the strip 8 terminates upwardly, short of the'upper end of cylinder 5. This will be understood to be a breaking-awayfor illustrative purposes only. The strip extends throughout the lengthof the cylinder, and in this particular, the showing of Fig. III iscomplete.

It will be perceived that with every rotation of the cylinder 5 theshaft 10 turns through a fraction of a complete rotation, and that thevalue of that fraction will be greater or less, according to thecircumferential distance between the strips 8 and 9 at the point atwhich the longitudinally movable block 3 stands. That distance, as hasbeen explained, is proportional to the square root of the distance atwhich block 3 stands from zero; that is to say, it varies as the squareroot of the diierential pressure under which the gas is flowing throughthe main. The extent of rotation of the shaft 10 then within the fixedtime interval of one complete rotation of cylinder 5 is an indication ofthe' quantity of gas which in that interval of timev has passed throughthe orifice. It will be apparent that if a tally were driven by shaft10, a suitable proportioning of parts (which might readily be done)would suflice to afford a reading in terms of volume of the quantity ofgas passed-uncorrected, however, for variations in other circumstances.

Under iield conditions, not only'does the dierential pressure vary in aiiowing stream of gas, but the static pressure varies too; and, otherthings being equal, the quantity of gas passing varies as the squareroot of the static pressure. It is common, in the practical measurementof gas, to obtain volumetric measurement, corrected more o1' lessperfectly for variations in dierential pressure, to observe by othermeans the variations in static pressure, and then to make correction ofthe first-named measurements by calculation from the observed value ofthe static pressure. I have perceived that, not only may I lemploy adevice, the duplicate of that already described, toexpress in angulareX- tent of the turning of a shaft, and with cor- A rection forvariations in static pressure, the quantity of gas which in a giveninterval of time passes an orifice, but I have further perlceived thatif I mount the cylinder of such a second device upon the driven shaft ofthe first, then the driven shaft of the second device will turn throughan angle which in the constant interval of time of one revolution ofcylinder 5 will be indicative of the quan-' .mentalities such as arediagrammatically indicated in the figure; and the arrangement of thecontact strips 88 and 99 upon the cylinder of the second device may beunderstood to be such that for each rotation of drum 55 the shaft 100turns through an angle which varies in value, proportionately to thesquare rootof the value of the stati-c pressure. When the two devicesare so organized, the shaft 100 will turn through an angle whose valuewill be indicative of the quantity of gas passed, with correction forvariations both in differential and in static pressure. If then shaft100 be caused to drive a tally 23, it is `merely a matter ofproportioning of parts to obtain direct reading of the so correctedvalue.

In the illustration afforded in Fig. I the lever 22 will-be understoodto swing upward as the static pressure increases, and in this respect tobe oppositely organized when compared with lever 2; for lever 2, as hasbeen explained, swings downward as theY differential pressureincreases".

There is still a third variable in the conditions which attend themeasurment of gas: namely, temperature. The volumeof a body of flowinggas, o-therthings being equal, varies with the temperature and by themeasurement formulas for the orifice and other like indirect meters thisvariation is inversely as the square root of the absolute temperature.Hence, when temperature variation is important as well as pressurevariation, a third device, substantially identical with the other two,may be imposed on the second. The third cylinder may be connectedintegrally upon the driven shaft of the second, the lever arm of thethird device may be made to swing in response to temperature variation,andthe driven shaft of the third 'device may be connected to the tally.Then, the parts having been properly proportioned,

`shaft 1000 associated with the cylinder 555 drives the tally 23. Thelever 222, which controls operation in the manner described of the partsborne by and associated with the cylinder 555, swings in response tovariation in the temperature of the gas under measurement, and to thatend a Bourdon spring 26 is provided, responsive to temperature change ofthe gas and connected to the lever 222, in such manner as to swing it.The strips 888 and 999, with which the cylinder 555 is equipped, are sorelatively positioned upon the cylinder that the space interval,circumferentially measured, at which the strips stand apart will, forevery position of the brush borne by the lever 222, afford correctionfor temperature variation.

Again, in the case of positive meter measurement also, temperature isoft-en a potent factor; but in this case, since the principle ofmeasurement is that of filling and emptying a constant space, themeasurement varies inversely as the absolute temperature. Hence, if thecylinder 5 be rotated in unison with rotatino` action of a positivemeter, the lever arm 2 eing a static-pressure arm and the lever arm 22a, temperature arm, a proper contact curve can be placed on cylinder 55,such that the tally it controls .will read in volume units as passed bythe positive meter, corrected for temperature aswell as pressure.

This is illustrated in Fig. V. In this figure, 10-is a shaft operated bya positive meter 105 and carrying cylinder 55. Cooperating with cylinder55, is a lever 22, responsive to variation in the static pressure of thegas under measurement, identically as already described in connectionwith Fig. I. Cylinder 555 is a cylinder borne by the shaft 100 which .isdriven through clutch mechanism by cylinder 55. Cylinder 555 operatesthe tally 23, in the manner indicated in describing the structure of Fig. IV, and, again, as in the case of structure Fig. IV, the lever 222,which is operatively associated with the cylinder 555, is caused toswing by av Bourdon spring 26, which Bourdon spring 26 will beunderstood to effect movement of lever 222 in re- 120 sponse tovariations in the temperature of the gas under measurement.

I have shown and described my invention in specific application tolapparatus for the measurement of gas. Manifestly it is much wider inapplicability.

In the commercial use of steam power it has become a common practice tosell steam, delivering it through conduits. Crdinarly, measurement is byvolume or weight, but the then, by a proper positioning of the Vcontactcommodity purchased is power, and power is only imperfectly expressed interms of volume or weight; for, manifestly, a unit volume of steam willcontain a greater or less numb-er of heat units (commonly termed B. t.u.), as the temperature is higher or lower. And, in order to ascertainthe number of heat units, it would be necessary to have some check upontemperature, and to correct the meterreadings in terms of volume, by thedata conv cerning temperature. This, however, is not ordinarily done;steam is sold by volume; and the inaccuracy of volumetric measurement asa measurement offbeat has been disregarded, because there has been nopractical way to do better. The apparatus of my invention may beemployed, to afford direct reading of the number of heat units deliveredby a stream of steam owing in a conduit.

lSince the pressure of saturated steam, and the heat units as well, aredeterminable from the temperature, the B. t. u. in flowing superheatedsteam can be measured directly.

Referring to Fig. I of the drawings, and

understanding that in the conduit an orifice plate, or like lineconstriction for other indirect meters, has been set, the lever 2 may beorganized to swing in response to variations in differential pressure asbefore, but now lever 22 is organized to swing in response to variationin temperature and the contact strip 99 is formed and placed on cylinder55 according to the combined relation of pressure and heat units totemperature in superheated steam; the range of rotation of shaft 100;and accordingly the reading of tally 23, will be indicative of thequantities-of B. t. u. delivered, and the connection may be so propo"-tioned that the tally will afford a reading in B. t. u. Since therelation between temperature of saturated steam and pressure is areciprocal one, it is optional whether temperature or pressure be usedin controlling the arm 22; but if pressure is used, the contact strip 99is changed accordingly, to correspond to the combined relation ofthe"square root of the static pressure and the heat units in terms ofthe pressure variable.

Again, in the transmission and delivery of electric energy, the unit ofpower is the watt. The number of watts delivered is the product of thecurrent strength, expressed in amperes, multiplied by the electromotiveforce, expressed in volts. Referring to Fig..

I of the drawings, one of the two levers, the lever 2 for example, maybe made responsive in its movement to the varying amperage of currentflow, and the other lever, the lever 22, may be made responsive to thevoltage;

strips 9 and 99 the instrument may be made to record and to aggregatethrough successive intervals of time the watts, that is to say thequantity of electric energy delivered. This is diagrammaticallyillustrated in Fig.` VI. A supply line for electric energy is indicatedat A B, and this may be understood to be a line carrying an alternatingcurrent. A lever 2 borne by the rotatable armature 35 of a motor 36,which is energized by the current carried by the line A B. The swingingof this lever will be responsive to variation in amperage, that is tosay, in the strength of the current iowing in the line A B. A secondlever 22 is borne by the rotating armature 38 of an electro-magnet 39,and the electromagnet 39 is so connected in the circuit A B thatvariations in voltage express themselves in the turning of the armature38. These two levers, 2 and 22, are organized in the manner alreadydescribed in connection with'Fig. I, and the strips 8 and 9 (88 and 99)upon the two cylinders 5 and 55 are so arranged that the shaft 100 willturn through an angle whose value will be accurately indicative of thequantity of electric energy passing in the line A B under conditionswhich may be variable, both with respect to current strength and withrespect to voltage. The shaft 100 drives the tally 23, and it becomes amatter of proportioning parts to obtain in the tally 23 direct readingin watts.

In dealing with petroleum derivatives (as a further example) iuidity isdependent on actual composition, on pressure, and on temperature; and ina given body, one ingredient being known, another and variableingredient may, by the manifest application of my invention, bemeasured. In the measurement of a petroleum derivative, variable inpressure and in temperature, it is manifest, -without furtherexplanation, that the structure illustrated in Fig.v V affords means forcorrection, to the end that measurement may be made with accuracy.

I claim as my invention:

l. Apparatus for measuring the flow of gas in a conduit, including, incombination with said conduit a -member having an extended face, meansfor causing said member to move through a distance which in a giveninterval of time is greater or less, according to variation in onecondition of a body of gas flowing in a stream through such conduit, ablock movable adjacent the face of said movable memberv and in adirection transversev to that in which the member moves, means wherebysaid block is moved in response to variation in another condition of thebody of gas flowing through such conduit, a second movable member, aclutch arranged between the movable member first named and the second,an electric control for said clutch, such control including mutuallyengaging parts borne by said block and by the movable member firstnamed, the range of engagement being greater or less according to theposition of the said block in its range of movement.

2. Apparatus for measuring the flow of gas in a conduit, including, incombination with said conduit, a member having an extended face, meansfor causing said member to move through a distance which in a given 5interval of time is greater or less, according to variation in onecondition of avbody of gas flowing in a stream through such conduit, ablock movable adjacent to the face of said movable member and in adirection transverse to that in which said member moves, means wherebysaid block is moved in response to variation in another condition of thebody ot gas iiowing through such conduit, a second movable member, aclutch arranged between the movable member first named and the second,an electric control for said clutch, such control including mutuallyengaging contact pieces borne by said block and by the movable memberrst named, one of the contact pieces extending obliquel bothto thedirection in which the bloc moves and to the direction' in .which thesaid movable member moves. v

3. Apparatus for measuring the flow of gas in a conduit, including, incombination with said conduit, a constantly moving member 'f having anextended face, a block movable adjacent to the face of said movablemember and in a direction transverse to that in which the member moves,means whereby said block is moved in response to variation in onecondition of a body of gas iowing in a stream through such conduit, asecond movable member having also an extended face, a clutch arrangedbetween the movable member first named and the second, an electriccontrol for said clutch, such control including mutually engaging partsonI the block and on the movable member lirst named, the range ofengagement being greater or less, according to the position of the blockin its range of movement, a second block movable adjacent to the faceofthe second movable member andlin a direction transverse to that in whichthe member moves, means whereby said second block is moved in responseto variation in another condition of the body of gas flowing throughsuch conduit, a third movable member, a clutch arranged between thesecond movable member and the third,

and electric control for lsaid clutch, such control including mutuallyengaging parts on the secondvblock and on the third movable member, therange of engagement being 5 greater or less, according to the positionof the lsecond block in its range of movement.

4. Apparatus for determining a resultant of a plurality of variablequantities, such apparatus including three movable members, of

o whichl the first `and second have extended surfaces, two blocksmovable severally adjacent to the extended surfaces of the first andsecond movable members and in directions transverse to the directions ofmovement of the irst and second movable members, means for causing eachblock to move in response to variations in the value of one of thevariadevices including each mutually engaging parts borne by the blockand by the movable member with which the bloc-k is associated, the rangeof engagement being greater or less, accordincr to the position of theblock in its range oi movement.

5. The structure of claim 4, together with means for driving the firstof said movable members at constant speed.

6. The structure of. claim 4, together with a tally with which the thirdof said movable members is connected.

7. Apparatus for determining the resultant of a plurality ofvariablequantities, such apparatus including three movable members, ofwhich the first and second have extended surfaces, two blocks movableseverally adjacent to the extended surfaces of the first and secondmovable members and `in directions transverse tothe directions ofmovement of the iirst and second members, means for causing each blockto move in response to varia-tion in the value 0f one of the variables,a. clutch arranged between the first movable member and the second, aclutch arranged between the second movable member and the third, twoelectric control devices, one for each of said clutches, such controldevices including each mutually engaging parts borne 'by the block andby the movable member with which the block is associated, the range ofengagement being of increasin extent, in the direction of movement o themovable member, at successive points in the range of block movement.

8. Apparatus for determining the resultant of a plurality of variablequantities, including two axially aligned rotatable members, two blocksmovable, one adjacent the face of each of said rotatable members,through a range transverse to the direction in which the members move,means whereby said blocks in such movements are responsive, each to oneof the variables whose resultant is to be determined, means for rotatingthe first of said members, a clutch arranged between the movable memberirst named and the second, an electric control for said clutch, suchcontrol including mutually engaging parts borne by the rst of saidrotatable members and by the companion block, the said parts being suchin shape and arrangement as to cooperate through a greater or lessportion of a rotation of the first rotatable member, according to theposition of the block along its range of movement, a third movablemember, movable means for imparting movement to the third movablemember, an electric control nol for the movement-imparting means lastnamed, such control including mutually engaging parts on the second ofsaid rotatable members and on the companion block,` the parts last namedbeing such in shape and arrangement as to co-operate through a greateror less portion of a rotation of the second rotatable member, accordingto the position of the block along its range of movement. lo 9.Apparatus for measuring gas, including two axially aligned rotatablemembers, two blocks movable, one adjacent the face of each of saidrotatable members, through a range l transverse to the direction inwhich the mem# bers move, means whereby said blocks in such movementsare responsive, each to one of the variable conditions of the gas undermeasurement, means for rotating the first of said members, a clutcharranged between the mov- Q0 able member first named and the second, anelectric control for said clutch, such control including contact pieceson the first of said rotatable members and on thecompanion block, the.said contact pieces being such in shape and arrangement as toco-operate during a greater or less portion of a rotation of the firstmember, according to the position of the block in its range of movement,a third movable member, means for imparting movement Y to said thirdmovable member, an electric control for the movement-imparting meanslast named, such control including contact pieces on the second of saidrotatable members and on the' companion block, the contact pieces lastnamed being such in shape and arrangement as to co-operate during agreater or less portion of a rotation of the second rotatable member,according to the position Of the block along its range of movement. 40In testimony whereof I have hereunto set m hand.

y ARCHER E. YOUNG.

